package com.mmall.concurrency.example.aqs;

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

@Slf4j
public class SemaphoreExample2 {

    private static int threadCount = 20;

    public static void main(String[] args) throws InterruptedException {

        ExecutorService exec = Executors.newCachedThreadPool();

        final Semaphore semaphore = new Semaphore(3);

        for (int i = 0; i < threadCount; i++) {
            int threadNum = i;
            exec.execute(()->{
                try{
                    semaphore.acquire(3);  //获取多个许可
                    test(threadNum);
                    semaphore.release(3);  //释放多个许可
                }catch (Exception e){
                    log.error("exception",e);
                }
            });
        }
        log.info("finish");
        exec.shutdown();

    }
    private static void test(int threadNum) throws InterruptedException {
        log.info("{}",threadNum);
        Thread.sleep(1000);
    }

}
